Daijiworld Media Network - Karkala

Karkala, Oct 16: Areca nut plantations in various parts of Karkala taluk have recently been affected by ‘Crohn’s Root Rot’ disease, causing significant losses to farmers as infected trees gradually wither and die. Officials from the department of horticulture have confirmed the symptoms of this disease in the affected farms.

The root rot is caused by the fungus phytophthora, primarily affecting older areca trees with a larger yield. The disease typically surfaces between August and September and persists until December or January. Environmental conditions such as alternating heat and rain, lower night temperatures, and dew promote the growth of this fungus.

In the early stages, green areca fronds start drooping and gradually turn yellow. These fronds remain green for an extended period before drying out, and the root ball eventually separates from the plant. Brown discoloration can also be observed at the base of the affected areca nuts. The fungus enters through the part where the leaf attaches to the stalk, eventually rotting the inner core of the plant, as reported by horticulture officials.

While the disease can be controlled through comprehensive management practices, improper use of Bordeaux mixture has also been linked to the spread of the infection. Farms where farmers have strictly adhered to the recommended control measures have seen a reduced impact. If the disease is identified early and necessary steps are taken, affected trees can be saved.

Farmers are advised to regularly apply nutrients based on soil test recommendations and, before the monsoon, treat their areca trees with a mixture of neem cake and Trichoderma. To prevent the spread of disease, infected fallen fronds should be collected and burned, and any dead trees must be cut down and destroyed. For trees showing early signs of infection, a 10% Bordeaux paste should be applied at the base, along with a 1% Bordeaux solution sprayed on nearby trees. In the initial stages of the disease, spraying affected leaves with 1.50 grams of 35% Metalaxyl in 1 liter of water, followed by 3-4 hours of sunlight, is crucial. Bordeaux mixture spraying should commence just before the monsoon and be repeated 2-3 times throughout the season, ensuring thorough coverage at the base of the trees.

Horticulture officials emphasize the importance of regular monitoring and adherence to these guidelines for effective disease control and crop protection.